A Ring Signature Scheme with Strong Designated Verifiers to Provide Signer Anonymity

Abstract

To provide more anonymous protection for the actual signer, the first ring signatures with strong designated verifiers is proposed in 2007. In the ring signature scheme with strong designated verifiers, any member in the ad-hoc ring is able to generate ring signatures, so ring signatures provide signer ambiguity to protect the actual signer’s anonymity. Moreover, only the designated verifier is convinced that the actual signer is one of the ring members. The other only guesses the actual signer may be one of the ring members and the designated verifier. If the other one guesses the actual signer being not only the ring members but also any possible ones, the scheme with strong designated verifiers provides the maximum anonymity protection for the actual signer. In order to convince the designated verifier, the designated verifier is still sure that the actual signer is one of the ring members. Therefore, the first ring signature scheme with strong designated verifiers is proposed to provide signer anonymity. In our scheme, the signer admission is also provided for the actual signer to prove who the actual signer is. The provable security analysis is provided to show that our scheme satisfies the ring signatures’ correctness and unforgeability.